0 means "there is no FCS in the packet data", 4 means "there is an FCS
in the packet data", -1 means "I don't know whether there's an FCS in
the packet data, guess based on the packet size".
Assume that Ethernet encapsulated inside other protocols has no FCS, by
having the "eth" dissector assume that (and not check for an Ethernet
pseudo-header).
Have "ethertype()" take an argument giving the FCS size; pass 0 when
appropriate.
Fix up Wiretap routines to set the pseudo-header. This means we no
longer use the "generic" seek-and-read routine, so get rid of it.
svn path=/trunk/; revision=8578
files to get that big.
From Thomas Wittwer and Matthias Nyffenegger:
Support for "ring buffer mode", wherein there's a ring buffer of N
capture files; as each capture file reaches its maximum size (the ring
buffer works only with a maximum capture file size specified), Ethereal
rolls over to the next capture file in the ring buffer, replacing
whatever packets might be in it with new packets.
svn path=/trunk/; revision=4323
Guy Harris